So, someone with more knowledge please school me. Obviously, discharging muzzle up is double-ungood.
Is a Series 70 essentially unlikely to do that if dropped? Does the firing pin spring reasonably eliminate the chance of a bounce back if it lands muzzle-up? I've read of an AR-pattern rifle making the loud noise when hitting the deck muzzle up (rare but possible), but that's a free floating pin.
I imagine the modified-Glock scenario is a case by case basis, depending on the details of the mods and failure.